The broad objective of this research proposal is to improve the health of elderly men and women by identifying more effective osteoporosis prevention and treatment strategies. Osteoporosis disproportionately affects the elderly and is associated with fractures that result in disability, death, and a large expenditure of health care resources. A growing number of interventions are available to prevent, diagnose, and treat osteoporosis. Cost-effective use of most such interventions requires selective targeting of high-risk populations, yet our previous research documents significant variation in clinical outcomes, cost, and intervention acceptance even among those at highest risk. Thus, the public health benefit of these interventions has yet to be fully realized. We hypothesize that this shortfall stems from multiple patient, provider and health system factors whose contribution to treatment and outcome variation is not yet understood. The proposed extension of AG 12262 entails four aims that will provide new information concerning variation in osteoporosis treatment and outcome. First, through surveys of patients and their healthcare providers, we will identify opportunities to improve intervention among elderly persons who have sustained a fracture; and will characterize correlates of long-term treatment continuation. Second, we will extend our study of fracture outcomes to a national sample to identify the patient, provider and health system attributes that contribute to variation in cost and adverse health outcomes. Third, we will develop a discrete state/event microsimulation model incorporating data from the first two aims to assess the cost-effectiveness of alternative osteoporosis interventions. This aim will also provide guidance to those planning future osteoporosis outcome studies through analyses addressing the correspondence between preference-based health outcomes measures and an osteoporosis-targeted health status instrument. Fourth, we will study the use of the microsimulation model as a tool for synthesizing evidence in patient-centered osteoporosis decision aids. Our proposed research will provide results useful in guiding both osteoporosis-related health policy and patient-centered decision making.